The present invention relates to a picture recording method for performing color or monochromatic picture recording from a color or monochromatic original and a picture recording apparatus for carrying out the method.
Generally known color picture recording apparatus include those of the silver salt photographic system, of the thermal transfer system, and of the electrophotographic system. Although being superior in picture quality, the silver salt photographic system is disadvantageous in that a long time is taken for the completion of a copy and the apparatus is expensive. The thermal transfer system is poor in picture quality and low in copying speed. Although being advantageous in that the picture quality is good and the copying speed is high, the electrophotographic system has a disadvantage in that the apparatus is expensive, and the inside of the apparatus gets dirty with toner powder to thereby increase the cost for maintenance.
Recently, photosensitive and pressure-sensitive recording paper suitable for recording paper or the like has been developed, for example, as disclosed in U.S. Pat. No. 4,440,846. The photosensitive and pressure-sensitive recording paper has microcapsules containing a coloring material, light-hardening resin, a light sensitizer, a light polymerization starting agent, etc., are applied on the surface thereof together with a developer agent for causing developing reaction with the coloring material in the microcapsules.
Conventionally, there have been following methods of recording picture information onto photosensitive and pressure-sensitive recording paper.
Method (1): A method in which scanning and exposing are performed directly on a photosensitive and pressure-sensitive paper by using light such as a laser which can be subject to switching.
Method (2): A method in which optical information is written on a photosensitive and pressure-sensitive paper through a microshutter, such as a liquid crystal shutter, disposed between the sheet and a continuously light emitting lamp.
However, there have been the following problems in those methods.
In the method (1), only a photosensitive and pressure-sensitive paper having a spectral sensitivity of 475 nm or less in wave length .lambda. can be manufactured at present. Accordingly, a selected one of an argon laser of a wave length .lambda.=351 nm, a krypton laser of a wave length .lambda.=351 nm, a helium and cadmium laser of a wave length .lambda.=325 nm, and an ultraviolet gas laser has been used as the laser light source acting as the scanning and exposing means. However, all those lasers are large-sized and expensive.
In the method (2), when a liquid crystal shutter is used as a microshutter, the liquid crystal per se is deteriorated by ultraviolet rays.
In a copying apparatus in which the photosensitive and pressure-sensitive paper is used as copying paper, there are such advantages that the copying speed is made high because the exposure on the photosensitive and pressure-sensitive paper is rapidly completed and the maintenance is easy because toner powder is not used. The photosensitive and pressure-sensitive paper described above is of the so-called self coloring type. Other than the photosensitive and pressure-sensitive paper of the self coloring type, photosensitive and pressure-sensitive paper of the transfer type, as described in U.S. Pat. No. 4,399,209, has been developed. The photosensitive and pressure-sensitive paper of the transfer type is such that the developer agent is not applied to the recording paper but only the above-mentioned microcapsules are applied onto the surface of the recording paper and a transfer sheet having a developer agent applied thereon is separately prepared. After the photosensitive and pressure-sensitive paper is exposed, the transfer sheet is laminated on the photo-sensitive and pressure-sensitive paper and then the lamination is pressed, so that an image is developed on the transfer sheet. Accordingly, the photosensitive and pressure-sensitive paper of the transfer type has the same advantage as that of the recording paper of the self coloring type.